<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Error</title>
</head>

<body>
    <script>
        console.log(a);//Uncaught ReferenceError: a is not defined
        // let b 
        // console.log(b.oac)//Uncaught TypeError: Cannot read property 'oac' of undefined
        // b = {}
        // b.xxx()//Uncaught TypeError: b.xxx is not a function
        const c =""""//Uncaught SyntaxError: Unexpected string

    </script>
</body>

</html>